11 61 730 BMW leak test for intake system (N54)

IMPORTANT: Overpressure and vacuum lines are identified by the size of the seals and colour-coded Red and Blue and must not be mixed up with each other.
Build up pressure with Blue color.
Generate vacuum pressure with Red color.
Mixing up the functions will result in damage to the engine.

Necessary preliminary tasks

Release upper section of intake air filter
Prepare BMW diagnosis system.
Start diagnosis program.
1. Drive
2. Engine electronics
3. Air supply
4. Boost pressure control or Perception Lack of power

Note on ordering:

Workshop equipment.
Workshop planning.
Workshop equipment catalogue.
Measuring and test equipment.
No. 81 29 0 426 464

Pressure measurement

Prepare BMW diagnosis system on diagnosis unit.

Screw in pressure sensor.
Overpressure connection (Blue).
Connect stimuli cables (3) to positive and negative.
Connect 12V battery cables (4) to vehicle battery positive and negative.

Fig 1: Connecting Stimuli Cables To Positive And Negative
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Secure seal plug (1) with union nut (2) in intake duct and seal.

NOTE: Twin-Turbo: both intake ducts must be sealed.

Fig 2: Identifying Seal Plug With Union Nut

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Insert Blue pneumatic hose (4) in pneumatic coupling (2) of sealing plug (1).

Seal plug (3) has no pneumatic coupling.

Fig 3: Inserting Blue Pneumatic Hose In Pneumatic Coupling Of Sealing Plug

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Vacuum pressure measurement

Prepare diagnosis tester on diagnosis unit.

Screw in pressure sensor.
Connect stimuli cables (2) to positive and negative.
Connect 12V battery cables (3) to vehicle battery positive and negative.
Controller for vacuum connection.
Vacuum connection (Red).

Fig 4: Connecting Stimuli Cables To Positive And Negative
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Calibration for vacuum pressure measurement

Seal stop cock (2) in direction of arrow.

Release lock nut on controller (1).

Carry out pressure adjustment in accordance with BMW diagnosis instruction.

Secure controller (1) hand-tight against turning.

Open stop cock (2) again.

Fig 5: Measuring Vacuum Pressure

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Connections on EPPC

Connection (VAC) to vacuum reservoir.
Connection (OUT) with ring to turbocharger.

Fig 6: Identifying Connections On EPPC
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Checking wastegate on cylinders 1-3

Detach vacuum line from EPPC (2), cylinders 1-3 (OUT).

Clamp off connecting line with suitable tool (1).

Attach vacuum line to pneumatic coupling (3) with Red pneumatic hose in direction of arrow.

Fig 7: Checking Wastegate On Cylinders 1-3

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Checking wastegate on cylinders 4-6

Detach vacuum line from EPPC (2), cylinders 4-6 (OUT).

Clamp off connecting line with suitable tool (1).

Attach vacuum line to pneumatic coupling (3) with Red pneumatic hose in direction of arrow.

Fig 8: Checking Wastegate On Cylinders 4-6

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Initial position (1) of wastegate linkage depressurized.

Wastegate valve open-end.

Fig 9: Identifying Wastegate Valve Opened

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Initial position (1) of wastegate linkage with vacuum pressure.

Wastegate valve closed.

Fig 10: Identifying Wastegate Valve Closed

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Checking wastegate valve (1) with vacuum pressure

Wastegate valve must be open-end without vacuum pressure.

The wastegate valves must close if a vacuum pressure is applied at the wastegate sockets.

Check shaft on turbine wheel for rotate-ability.

Fig 11: Checking Wastegate Valve With Vacuum Pressure

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Checking pop-off valves

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Necessary preliminary tasks

Remove both pop-off valves

NOTE: To check the function of the pop-off valves (2), it is necessary to build up vacuum pressure at the valves.
Establish vacuum pressure with the BMW auxiliary diagnosis unit - vacuum.

Fig 12: Checking Pop-Off Valves

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Connect vacuum hose (3).

Establish vacuum pressure at 500 mbar.

Plunger (1) must visibly release the opening in the direction of the arrow as far as it will go.

IMPORTANT: Plunger (1) must maintain this position while vacuum pressure is being created.
If this is not the case, replace the pop-off valve (2).

Assemble engine.

Observe BMW diagnosis instructions.